Avalanche Forecast
Issued: Jan 19th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Deep Persistent Slabs and Loose Dry.
Benjamin Firth,
Parks Canada
Think twice about jumping into complex avalanche terrain as the recent cold snap has weakened the snowpack especially in thinner areas.
Summary
Weather Forecast
Temperatures will continue to warm over the next few days. Winds will become westerly and increase to Strong values by Monday evening.
Monday: Trace amounts of snow High -6 Freezing levels rising to 1500M
Tuesday: Cloudy with sunny periods and isolated flurries.
For more info: Avalanche Canada Mountain Weather Forecast
Snowpack Summary
Continued faceting of snowpack. Up to 10cm of settled recent snow may not be bonding well to the upper settled pack. This overlies a weakening mid-pack comprised of varied facet forms. This provides some questionable bridging over the basal facets and DH. HS average at TL: ~135cm.
Avalanche Summary
No new natural avalanches at Marmot and Maligne were observed today. Jan 18th Marmot had an explosive result producing a size 3 out of an alpine north facing feature that went to ground. Start zones were crossed loaded features.
Confidence
Intensity of incoming weather systems is uncertain on Monday
Problems
Wind Slabs
New wind slabs forming on easterly aspects at ridgetop along with cornice growth. Old and buried wind slabs on all aspects in the alpine could become more reactive as temperatures warm.
- Avoid lee and cross-loaded terrain near ridge crests.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
The recent cold weather has promoted facetting and weakening of the snowpack compromising the bridging strength. Potential for triggering these deeper layers could increase as temperatures warm.
- Avoid convexities or areas with a thin or variable snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Dry
Up to 15cm new snow may not be bonding well to previous surface. As temps warm, expect continued dry loose sluffs out of steep terrain.
- Sluffs may trigger deeper instabilities.
- Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 20th, 2020 4:00PM
